TM 5-3810-288-12
the horns operate properly. Check visible wiring to horn
Clutch Service and Adjustment Shaft
buttons for worn or frayed insulation. Report deficiencies
to organizational maintenance.
a. Service. Keep the mechanical components of
the reversing shaft clutch and the horizontal swing shaft
3-18. Tachometer
clutches clean and dry. Do not allow hydraulic fluid to
come into contact with clutch linings. Both swing
With the engine running, check tachometer readings. At
clutches and the reversing shaft clutch are identical.
low idle, the reading should be about 500 rpm
(revolutions per minute). At high idle, the reading may
b. Adjust. Refer to figure 2-36 and place the
be as high as 2,000 rpm. Under full load, the reading
control lever for the clutch being adjusted in the centered
should be about 1800 rpm. Report any major deviations
(neutral) position. Refer to figure 3-11 and adjust the
to organizational maintenance.
reversing shaft clutch or the horizontal swing shaft
clutch.
3-19. Rear Drum Clutch Service and Adjustment
3-23. Front and Rear Drum Brake Service
a. Service. Keep the mechanical components of
and Adjustment
the clutch clean and dry. Do not allow hydraulic fluid to
a. Service. Keep the mechanical components of
come into contact with clutch linings.
the rear drum brake clean and dry. Do not allow
hydraulic fluid to come into contact with brake linings.
b. Adjust. Refer to figure 2-36 and place the rear
b. Adjust. The adjustment of both of these brakes
drum clutch lever in the centered (neutral) position.
is identical and is done with hydraulic pressure off. No
Refer to figure 3-9 and adjust the rear drum clutch.
pressure should be placed on the operating foot pedal.
Position the clutch as desired by "tapping" the engine
Refer to figure 3-12 and adjust the front or rear drum
start push button, with the ignition switch in the OFF
brake.
position.
3-24. Boom Hoist Brake Service and Adjustment
3-20. Front Drum Clutch Service and Adjustment
a. Service. Keep the mechanical components of
a. Service. Keep the mechanical components of
the clutch clean and dry. Do not allow hydraulic fluid to
the boom hoist brake clean and dry. Do not allow
come into contact with clutch linings.
hydraulic fluid to come into contact with brake linings.
b. Adjust. Adjustment of this clutch is identical to
the adjustment of the rear drum clutch, except that the
b. Adjust. Refer to figure 3-13 and adjust the
front drum clutch lever instead of the rear drum clutch
boom hoist brake.
lever (fig. 2-36) must be placed in the centered (neutral)
Warning: Always lower the attachment to the
position. Refer to figure 3-9 and adjust the front drum
ground before attempting to adjust the boom hoist
clutch. Position the clutch as desired by "tapping" the
brake. Serious damage to the equipment or injury to
engine start push button, with the ignition switch in the
personnel may otherwise result.
OFF position.
3-25. Swing Broke Service and Adjustment
3-21. Boom Hoist Clutch Service and Adjustment
a. Service. Keep the mechanical components of
a. Service. Keep the mechanical components of
the swing brake clean. Keep lock-nuts tightened.
the boom hoist clutch clean and dry. Do not allow
hydraulic fluid to come into contact with clutch linings.
b. Adjust. Refer to figure 2-36 and place the
swing brake lever in the released position. Refer to
b. Adjust. Refer to figure 2-36 and place the
boom hoist clutch lever in the centered (neutral) position.
Refer to figure 3-10 and adjust the boom hoist clutch.
Note. The swing brake is not used to stop the revolving
frame from swinging while the machine is in operation. It is
used solely to prevent the revolving frame from turning while
3-22. Reversing Shaft and Horizontal Swing
the machine is not in use, such as when it is being moved from
place to place.
3-10
